Histochemical evidence of the catecholamine-associated nervous system in certain schistosome cercariae

Abstract

The localization of catecholamines was documented in the cercaria of Schistosoma mansoni and S. japonicum by a fluorescent histochemical method using glyoxylic acid (GA). Cell bodies and nerve fibres were spatially visualized in whole-mount preparations, and the fluorescent traces were investigated. The nervous system was bilaterally symmetrical, showing a similar formation in both species. A pair of cerebral ganglia with a transverse commissure showed a complex network of fluorophores, and each radiated two sets of anterior and posterior longitudinal nerve cords. A third pair of longitudinal nerve cords was observed in the most dorsal area. A posterior transverse commissure was seen to connect the posterior longitudinal cords, and the posterior terminals of the postero-ventral cords communicated with the tail cords. The glyoxylic acid-induced fluorescence (GAIF) method was demonstrated to be quite suitable for neuroanatomical and neurophysiological investigations of larval forms.

Catecholamines demonstrated by glyoxylic-acid-induced fluorescence and HPLC in some microturbellarians

“…It can be concluded from our results and from recent studies on other flatworm species (Joffe & Kotikova, 1987;Kotikova & Joffe, 1988;Orido, 1989;Buchman & Prento, 1989) that catecholamines seem to be neurotransmitters generally occuring in flatworms. Their function, however, is unknown.…”

“…The method has been shown to be suitable for whole-mount studies of the neuroanatomy of small flatworms (Joffe & Kotikova, 1987;Kotikova & Joffe, 1988;Orido, 1989;Buchman & Prento, 1989). It is sensitive, capable of detecting picomolar quantities of neurotransmitters, and permits fast and exact localization of CA (catecholaminergic) neurons and fibers in the nervous system.…”

“…For the parasitic flatworms, different roles, including release of 5-HT, neurotransmitter or neuromodulator influence on muscle control, and a role as sensory transmitters, have been suggested (Bennett & Bueding, 197 1;Gianutsos & Bennett, 1977;Pax et al, 1984;Orido, 1989). HPLC Dopamine has been found to play a prominent role as a neurotransmitter substance in many invertebrates.…”

“…In recent years the use of the GAIF method (glyoxylic-acid-induced-fluorescence method) has produced added evidence for catecholamines in flatworms (Joffe & Kotikova, 1987;Kotikova & Joffe, 1988;Orido, 1989;Buchman & Prento, 1989). This method is very sensitive and permits a more exact localization of monoamines than the classic formaldehyde-induced-fluorescence method (Bjdrklund et al, 1972;Lindvall& Bjorklund 1974;.…”

Glyoxylic acid induced fluorescence in the nervous system of Gyratrix hermaphroditus (Kalyptorhynchia, Polycystididae)

“…The GAIF-method was shown to be suitable for the whole-mount studies of the neuroanatomy of the flatworms (Kotikova & Joffe, 1988b ;Orido, 1989 ;Buchman & Prento, 1989 ;Gustafsson & Eriksson, 1991 ;Joffe & Kotikova, 1991) . It was in the representatives of the Polycystididae -Gyratricella attemsi (Gyratricinae) and Acrorynchides robustus (Acrorhynchinae) that the first data on the distribution of CA recorded by GAIF method in the Kalyptorhynchia were obtained (Joffe & Kotikova, 1989a ; .…”